1. Field of the Invention
The present invention relates to an optical fiber connector assembly, and particularly to an optical fiber connector with simplified assembly mechanism having greater structural strength and an improved mode marking feature.
2. Description of the Prior Art
The prior art as known is exemplified by FIG. 1. It is not known whether any patents exist that describe the structure of FIG. 1. Accordingly, a detailed description of FIG. 1 will aid an understanding of the invention forming the subject matter hereof. In FIG. 1, there is shown a plan view of a prior art optical fiber connector, portions being displaced or "exploded" for greater clarity. The connector includes housing shells 1. Extending from the rear end of the shell (left end as viewed in FIG. 1), is a cable receiving passageway 2 which is threaded externally and is adapted to be engaged by nut 4. Also included as a part of the housing is a groove 5 which is disposed at a proper position in relation to the passageway to receive an interlocking flange.
A bushing 6 adapted to hold the fiber cable 9 has a flange 8. A passageway 7 is formed through the bushing and the flange through which the cable 9 extends. The strength member yarn 10, constituting a synthetic resinous material sold under the trademark KEVLAR, is adapted to be disposed between the external surface 11 of the bushing's body at its front end and the inner surface of a metal socket or sleeve 12 which is fitted over the bushing body in an interference fit to hold the strength member yarn in a fixed position. There is a projecting rib 13 extending from the external surface of the bushing body which is used to hold the cable 9 in a fixed position when the socket 12 is fitted over the bushing, pressing the projecting rib downwardly into the passageway 7 and into clamping relation with the cable 9. The shells 1 are held together when the bushing 6 is loaded into receiving passageway 2, and nut 4 is then turned onto the external threads 3.
Because the fiber cable is of indefinite length, the fiber cable must be threaded through the nut as a first step of the assembly. Unfortunately, the assembly line worker is prone to leave the nut off, and does not discover the omission until the rest of the assembly has been completed. When this occurs, all the assembled components must be disassembled to start the whole assembly procedure over again by first threading the cable through the nut. Accordingly, one of the objects of the present invention is to provide an optical fiber connector structure that provides means for eliminating this potential problem.
To implement the metal socket 12 requires a special tool, thus increasing the cost of the connector in time and money. Accordingly, another object of the invention is the provision of a connector that is economical to fabricate and readily assembled without special tools.
Furthermore, the locking structure of the prior art housing is based on a single screw locking mechanism that is not secure enough to retain the shells tightly clamped after an interval of utilization. Accordingly, a still further object of the invention is to provide an optical connector structure that will remain tightly clamped for its entire life.
It should also be noted that the mode marking system in the prior art connector employs a cavity 14 disposed on the housing shell 1 to receive a single-faceted key element to mark one of the many possible function modes. As a consequence, several other cavities disposed on the dust-reject cover are required by the prior art to receive the unused mode marking key elements. In practice, the dust-reject cover is attached to the fiber cable by a cord. As a result, many of the mode marking key elements can be lost very easily. It is therefore a still further object of the invention herein to obviate this disadvantage.
The ferrule 16 of the prior art includes a flange 17 disposed at the front end thereof, a coil spring 19 surrounding the body portion 18, followed by a stop collar 20 and a split spring retaining ring 21 engaging a groove at the rear end of the ferrule to hold the coil spring between the flange and stop collar. The flange and stop collar of the ferrule are then received in a nest 22 of the housing shell 1 to form an elasticity buffer. However, the structure and the size of the prior art ferrule make the assembly inconvenient and costly. Accordingly, yet another object of the invention is to simplify this ferrule structure.
The invention possesses other objects and features of advantage, some of which, with the foregoing, will be apparent from the following description and the drawings. It is to be understood however that the invention is not limited to the embodiment illustrated and described since it may be embodied in various forms within the scope of the appended claims.